Low water warning signal and cutoff system



Jan. 18, 1955 L. H. HUCKABEE 2,700,153

LOW WATER WARNING SIGNAL AND CUTOFF SYSTEM Tlfi l- 9 Filed Sept. 22,1952 INVENTOR LUTHER H. HUCKABEE United States Patent O LOW WATERWARNING SIGNAL AND CUTOFF SYSTEM Luther H. Huckabee, Memphis, Tenn.

Application September 22, 1952, Serial No. 310,859

1 Claim. (Cl. 340244) This invention relates to new and usefulimprovements in safety devices, particularly for use with liquid cooledengines of either the automotive or stationary types, and particularlyrelates to a system adapted to indicate the loss of coolant from thereservoir of cooling systems for such engines and to eifect cut-oif ofsuch engine when the coolant level in such reservoir has dropped belowthe danger level, the point and beyond at which continued operation ofthe engine would result in damage thereto.

In particular this system relates to electrical means including contactsextending into the coolant reservoir, such as the water radiator of amotor vehicle, with the contacts being arranged at different levels inthe reservoir and being coupled to a signal device and a cut-off devicein the manner hereinafter described to sequentially eifect basicpurposes of the invention. The coolant of the reservoir is employed as aportion of the respective circuits involved and the present inventionutilizes the lowering of the coolant level below contact with therespective contacts to effect interruption of the individual circuits.

Multi-level electrical signalling devices have heretofore beencontemplated and attempted, but these devices have proven ineffectiveand inefiicient, and in addition have not provided for insurance againstrestarting of the engine with an inadequate supply of coolant on hand,nor have such prior devices taken into account the condition obviouslypresent in moving engines, such as those of motor vehicles, in which thewater in the reservoir by sloshing through physical movements and changeof attitude of the reservoir could intermittently reestablish theoriginal circuits and thus permit the undesired reoperation of theengine and resultant damage.

The principal object of the present invention is to provide incombination with an engine having a liquid cooling system an electricalsystem for signalling a preliminary loss of coolant from such coolingsystem and for effect ing cut-off of the engine operation uponsubstantial loss of coolant from the system below a level of safeoperation.

A further object of the invention is to provide in connection with suchengine cut-off means, means for maintaining the engine in cut-01fcondition during the absence of adequate coolant supply in the coolingsystem reservoir.

A further object of the invention is to provide a water loss signallingand cut-off system of efiicient character which may readily and simplybe installed upon conventional engines without the necessity ofsubstantial modification thereof.

A further object of the invention is to provide a signal circuit coupledto a contact maintained in the coolant reservoir of the cooling systemat an upper level to signal the condition of a loss of coolant in orbelow said upper level and a cut-off circuit coupled to a contactextending into the reservoir to a lower level adapted to eflect cutoifof the engine operation through interrupting the ignition circuitthereof, interruption of the ignition circuit being accomplished througha relay normally maintaining the circuit in closed condition, the sameoperation interrupting electrical supply to the relay, insuringmaintenance of cut-off condition in the absence of adequate coolant inthe cooling system reservoir.

Other and further objects of the invention will become apparent from aconsideration of the attached specification upon reference to theaccompanying drawings, in which:

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Fig. 1 is a schematic wiring diagram illustrating the arrangement of thepresent invention.

Fig. 2 is a somewhat schematic plan view illustrating a typicalinstallation of the invention in connection with a motor vehicle.

Fig. 3 is a fragmentary diagram illustrating a modification ininstallation of the invention.

Referring now to the drawings in which the various parts are indicatedby numerals, the present invention is adapted for use in connection withan engine such as the engine 11, which, in the typical installationshown in the drawings, form a part of an automobile 13.

Engine 11 is of the liquid cooled variety, including a liquidcirculating system which includes a source of supply, such as theradiator 15, which is connected in conventional manner as by hose 17 tothe water jacket of engine 11.

As is conventional automobile 13 includes a source of electrical powersupply such as the battery 19 which provides electrical current to thevarious instrumentalities of the vehicle, including the ignition circuitof the vehicle, which ignition circuit in conventional manner includesigniton switch 21, which is interposed in the line 23 which is connectedto one side of battery 19 leading to various electrically operatedinstrumentalities connected with the automotive vehicle, such assymbolized by the ignition coil 25 which may be connected to theopposite side of the battery 19 as by lead 27.

By a line 29 branching from line 23 current from battery 19 is deliveredto a synchronous vibrator power pack 31 by which power pack the voltageof the current from battery 19 is stepped up to approximately 250 volts.A lead 33 is connected to line 23 beyond ignition switch 21 and isconnected to a terminal 35, to which is electrically coupled a shiftableswitch arm 37A forming one side of a double pole switch 37, switch arm37A being adapted to be shifted and make contact alternately with thecontacts 39, 41, the contacts 39, 41 being respectively connected tosuitable signals such as lights 43, 44 as by leads 45, 46. Lights 43, 44may be conveniently mounted as upon the dash-board of automobile 13.Shift of switch arm 37A to and from contact 39, from and to contact 41is controlled by a relay 47, which is connected as by lead 49 to thesecondary of the power pack 31. The opposite side of relay 47 isconnected as by lead 51 to a contact 53 carried by a suitable fitting 55which is adapted to be engaged into an opening formed in the shell ofradiator 15, with the contact 53 extending into the interior or"radiator 15 and being arranged so as to normally extend into the watercontained in the radiator when the radiator is filled to capacity,contact 53 terminating at an upper level of radiator 15 indicated by thedotted line 15A, which, while a safe operating level is undesirablebecause the supply of water will have diminished in order to be loweredto such level indicating the imminence of danger.

Coupled to the line 49 is a line 57 which is connected as by lead 59 tothe input of a second relay 61. Branching from line 57 is a supplementalline 63 which is likewise coupled to lead 59 and thus to relay 61.Interposed in line 57 between the connection of line 63 to the line 57and the connection of line 57 to lead 59 is a switch 65A forming oneside of a double-pole switch 65, the operation of the switch 65 beingcontrolled by relay 61. interposed in line 63 is switch arm 37B formingthe other side of the first double-pole switch 37, the movement of whichis controlled by the relay 47. The opposite side 65B of the double-poleswitch 65 is interposed in ignition circuit line 23. A lead 67 isconnected from the relay 61 to a second and lower level reservoircontact 69 which is provided with a suitable fitting 71 by which thecontact is mounted in radiator 15 and extended through the shell of theradiator into the interior thereof, the contact 69 being disposed toextend to a low or danger water level, indicated by the dotted line1513, at or below which operation or" the engine 11 will subject theengine to potential danger.

It thus will be seen that the radiator 15 properly filled with water orother suitable coolant to a level at or above the upper signal level15A, the entire device will permit the ignition circuit of theautomobile to be operative. Thus when the switch 21 is closed the powerfrom battery 19 is delivered to the vibrator pack 31 and a circuit isthen completed through lead 49 to relay 47, thence through lead 51 tothe contact 53, the water in the reservoir with which the contact 53' isintimately associated, becoming a part of the circuit and completingsame.

With the circuit through relay 47 thus complete, upon the closure ofswitch 21 the relay 47 is effective to shift double-pole switch 37 so asto swing switch arm 37A from light contact 41 to light contact 39, thusenergizing light 43, which preferably is a green light indicating thatthe water level in radiator is at a satisfactory level. Simultaneouslyswitch arm 37B of the switch 37 is moved to closed position and effectsconnection through lines 49, 57 and 63 into lead 59 and relay 61, thiscircuit being completed through lead 67 to contact 69; the water inradiator 15 again serving as an element of the circuit and completingthe same. With the encuit thus completed relay 61 is effective to shiftthe double-pole switch 65, moving the switch arm 653 to closed position,thus completing the ignit on circuit through line 23, switch 21, theinstrumentalitres of the motor vehicle, as the ignition coil 25, andline 27 back to the battery 19.

The shift of switch 65 by relay 61 is also effective to close switch arm65A, completing an additional circuit into relay 61 through line 57,switch 65A, and lead 59.

If during the operation of the engine the water level in radiator 15falls below the upper signal level 15A it will immediately be seen thatcontact with contact 53 is broken, thus interrupting the circuit throughthe re lay 4'7 and releasing switch 37 from the effect of the relay. Itwill be seen that the sw1tch 37 s preferably urged toward open position,spring 37C being indicated in Fig. l for this purpose, and the effect ofrelay 47 upon switch 37 being released, the switch will be shifted tothe opposite position in which sw1tch arm 37A 1s moved into contact withcontact terminal 41, effecting through lead 46 a complete circuit intothe light 44, which is preferably a red light, thus immediatelylndlcatlng by a visual signal that the water in radiator 15 has fallenbelow the level 15A.

Simultaneously with this shift of the switch 37, the switch arm 37B isswung to open position interrupting the circuit into relay 61 throughline 63. This opening of switch 373, however, does not interrupt theoperation of relay 61 inasmuch as the circuit through line 57, andswitch 65A continues complete. if during continued operation of theengine the water level in radiator 15 should continue to fall to a pointbelow the level 15B, beyond which point further operation of the enginewill be dangerous due to the probable over heating as a result ofinadequacy of coolant supply, the circuit into relay 61 will be brokenby removal of the water below the contact point of contact 69. With thecircuit to relay 61 thus broken the effect of the relay upon the switch65' is released and as this switch preferably is normally spring-urgedtoward open position, a spring 65C being indicated in Fig. l, the switch65 moves from the circuit closing position in which the switch arm 65Bcornpletes the ignition circuit through line 23, thus interrupting thatcircuit and interrupting engine operation.

Simultaneously with this shift of spring 65 the switch arm 65A forming apart of the remaining c'ncuit into relay 61 is similarly shifted to openposition, thus interrupting the circuit into relay 61 in addition to theinterruption from drop in the water level. As a result it will be seenthat it is impossible to again start the engine until such time as thewater level has been restored to the upper signal l vel 15A or above, itbeing observed that merely filling the radiator with water to the level15B and below the level 15A will be ineffective to reestablish thecircuit due to the open condition of switch 65A, preventing theenergizing of relay 61 and consequently preventing the closure. ofswitch 65B, thus maintaining the ignition circuit through line 23 inopen condition.

It thus will be seen. that if the water level has dropped below thelevel 153 the ignition circuit is efiectively interrupted and maintainedin interrupted condition, with the result that accidental tilting 'ofthe reservoir 15, shifting the water level in the reservoir, will not beeffective to reset the ignition circuit for further operation. As aresult sloshing of the water in radiator 15 will not be effective toreestablish the circuit intermittently and in undesired manner. It willbe observed, however, when the Water level is again raised to the level15A, or above, the initial circuit into relay 47 will be reestablishedand with ignition switch 21 closed the sequence of operation whichoccurs substantially simultaneously will result, as heretofore set out.

In Fig. 3 a variation in application of the invention is illustrated andthe installation is there shown as directly operating upon a fuelcut-off device. Fuel deliver means are symbolically illustrated by thefragmentary induction pipe 111 in which is mounted a butterfly valve113, the movement of the butterfly valve being controlled as by an armlb swingably supported in usual fashion from the induc ion pipe. Asolenoid 117 is provided with a plunger core 119, the solenoid beingadapted when energized to withdraw the plunger core 119 into retractedposition and when the solenoid is deenergized the core is urgedoutwardly into extended position as by a compression spring 121. Thesolenoid and core are positioned adjacent the valve arm 115 so that uponextension of plunger core 119 it is moved into abutment with the valvearm effecting shift of the valve arm to closed position when thesolenoid is deenergized as illustrated in Fig. 3. Solenoid 117 iselectrically connected as by a lead 123 to power line 23 and theopposite side of the solenoid is connected as by a lead 127 into thereturn line 27.

It will be seen that the operation of the installation illustrated inFig. 3 is accomplished in substantially the same manner as thatdescribed heretofore for the installation of Fig. l, and that upon theclosing of switch B in the manner heretofore described, completing thecircuit through lines 23 and 27, the circuit into the solenoid 117 iscompleted through leads 123, 127. energizing the solenoid and effectingretraction of plunger core 119, removing the restraint upon valve armand permitting free operation of the valve arm 115 and of the valve 113.When the circuit is broken by the opening of switch 653, in the mannerheretofore described as a result of the loss of coolant in reservoir 15,solenoid 117 is deenergized, the plunger 119 extended and restraint uponvalve arm 115 holding valve 113 in closed position is effected.

It will be understood that the induction pipe and butterfly valve isintended as symbolical of fuel induction means and that the solenoidcut-off will be effective with other types of fuel induction means' Itwill further be understood, and is believed to be apparent, that theinvention may be equally applied to other forms of electricallycontrolled cut-off means, such as for example electrically operatedvalves or the lilte.

I claim:

A liquid-level responsive safety device for an engine which includes aliquid cooling system having a liquid reservoir, comprising a pair ofcontacts disposed in said reservoir respectively at upper and lowerreservoir levels, a source of low voltage, direct current, electricalpower, electrical circuit means connecting said source of powerrespectively to said contacts, said circuit means including a firstrelay connected to the upper level said contact, a second relayconnected. to the lower level said contact, first switch meansinterposed in said circuit means between said source of power and saidsecond relay, said first relay being positioned to operate said firstswitch means and complete the circuit to said second relay when saidfirst relay is energized, a'bypass relay circuit connecting said sourceof power to said second relay independently of said first relay, saidbypass circuit including a normally open switch, a main engine powercircuit connected to said source of power including a switch, saidbypass circuit switch and said power circuit switch being coupled forconcurrent circuit closing movement upon energizing of said second relayto complete said main power circuit and said bypass circuit, a dangersignal, signal circuit means connecting said signal to said main powercircuit, said signal circuit means including a signal switch coupled tosaid first switch means for operation concurrently therewith andpositioned to complete said signal circuit on deenergizing of said firstrelay, loss of liquid in said reservoir below said upper leveldeenergizing said first relay to complete said signal circuit andinterrupt the first mentioned circuit to said second relay, said bypasscircuit maintaining energizing connection of said second relay to saidsource of power and concurrently maintaining said main power circuit,loss of liquid in said reservoir below said lower level interrupting thesecond relay circuit releasing said bypass switch and said power circuitswitch to interrupt said main power circuit.

References Cited in the file of this patent UNITED STATES PATENTS1,144,101 Bradbury June 22, 1915 Duharnel June 3, 1924 Warrick July 22,1941 Withrow Sept. 14, 1943 Pinkerton Sept. 18, 1945 Spierer May 1, 1951

